Again, you don't get it. You are analyzing everything from your 2020 perspective, and acting as if one book/movie from a low-level operative is the bible of the Mafia.
Gritty stories about the mob have been depicted in movies for quite some time, you can go back to The Public Enemy (1931) or Scarface (1932) to see shocking (for the times) and gritty (for the times) depictions of mob activity. You would even be happy to see that the mobsters are portrayed as violent and "not romanticized".
As for your misunderstanding of what the depiction of real events means, you are still wrong. The Godfather is not "inspired by" real events, it actually uses multiple actual events. Not just a character. All the characters are based on real people and all of the plot is based on real events. Yes, in 1969, Mario Puzo could not state, from personal experience, that he witnessed all of the events, but his plot involves real events. And, yes, 20 years later, Henry Hill was able to tell his story with more certainty as to people and places because, by that time, the Mafia had become soft about punishing those who broke Omerta.
I'm not sure what you don't get. Dozens and dozens of individuals, since 1969, have verified the correlations between the events in Mario Puzo's book and the real-life events. When you say "the events in the movie were not based on anything that happened in real life" you are wrong. And don't try to split hairs. Godfather I and II are based on the book. Coppola didn't invent any extra plot for the movie that wasn't already in the book.
It's hilarious to watch you try to defend Goodfellas' factual authenticity for certain events THAT HENRY HILL DID NOT EVEN WITNESS. Look, maybe Goodfellas is 100% correct, and maybe it's not, but YOU certainly don't know. Henry Hill was KNOWN for lying, he was KNOWN for exaggerating, so let's not pretend like the killing of Pesci's character is "completely accurate". It's about the same as what Scorsese did in The Irishman. Is that really how Hoffa was killed and disposed? Who knows, but at least The Irishman is based on an account of a person WHO ACTUALLY CLAIMS TO HAVE BEEN INVOLVED IN THE MURDER. That is absolutely NOT the case with Henry Hill, who was NOT present when Tommy DeSimone was killed.
The bottom line is that Scorsese AS A FILMMAKER invented a number of depicted events in Goodfellas, just as he did in The Irishman. You can try to blame Coppola for the same thing, but he was much more faithful to Mario Puzo's book than Scorsese was to Nicholas Pileggi's book (****, Scorsese even changed the title from Wiseguy to Goodfellas). That's just basic truth.
If you want to "like" Goodfellas more than Godfather I and II, that's your right, but don't claim victory based on falsehoods, such as "Goodfellas is more factually accurate". If you found it more entertaining, that's up to you, but stop falsely claiming that I and II are overrated or based on hype or based on being "first of their kind" or any other garbage 2020 revisionist complaint.